A Victorian detective accused of punching a handcuffed man to the stomach has maintained he was acting lawfully.
Cameron Curlis was a detective senior constable for Victoria Police when the alleged unlawful assault occurred in Melbourne's northwest on January 5, 2022.
He has pleaded not guilty to the charge and is on trial in the County Court in Melbourne.
Prosecutor Elizabeth Johnson on Wednesday told the jury Curlis punched Gurjant Singh while he was handcuffed and affected by capsicum spray.
Curlis and another detective had earlier stopped Mr Singh's vehicle because there were outstanding warrants for his arrest, the jury was told.
After he was handcuffed and placed in the police divisional van, Mr Singh complained he was feeling nauseous so they let him step outside.
The jury was told Mr Singh then ran from the scene, with two officers giving chase and Curlis and the other detective following by car.
Mr Singh was found in a St Albans driveway, hiding behind a vehicle.
One of the officers used capsicum spray to stop Mr Singh and it's alleged Curlis then punched him to the stomach while he was still handcuffed.
Curlis allegedly moved a CCTV camera before the assault so it was pointed in a different direction, Ms Johnson said.
"We say that was a deliberate act because he had formed an intention to assault Mr Singh," she told the jury.
But Curlis' barrister Barnaby Johnston told the jury his client did not punch Mr Singh.
Instead, he swung his forearm with force towards the other man, Mr Johnston said.
"We say he was acting lawfully in his duty as a police officer when he applied that force," the defence barrister told the jury.
Mr Singh and the other police officers who were at the scene will give evidence in the trial.
The hearing before Judge Pardeep Tiwana is expected to run for five days.